JPS59191323A - Semiconductor substrate - Google Patents

Abstract

PURPOSE:To relieve the strain of the circumference of a substrate and avoid slipping by making the circumference region of the single crystal semiconductor substrate composed of polycrystalline semiconductor. CONSTITUTION:The circumference region of a single crystal silicon substrate 3 is composed of polycrystalline silicon 4. Then the strain of the circumference of the substrate is relieved by the silicon 4 and slipping of the substrate 3 is avoided.

Description

[Detailed description of the invention] The present invention relates to a semiconductor substrate.

The purpose of the present invention is to suppress crystal defects occurring during the manufacturing process of semiconductor devices to an extremely low level.
An object of the present invention is to provide a semiconductor substrate that improves the electrical characteristics of a semiconductor element and allows a high-yield semiconductor device to be obtained.

Conventional single-crystal semiconductor substrates are single-crystalline to the periphery of the substrate, so crystal defects from the periphery of the substrate occur during the semiconductor device manufacturing process (crystal defects that enter from the periphery of the substrate are mainly defects called slip lines, hereinafter abbreviated as slips). There is a problem in that the electrical characteristics of the semiconductor device are deteriorated and the yield rate is lowered.

FIG. 1 is an example of a conventional single crystal silicon substrate.

The single crystal silicon substrate is made of single crystal silicon 1 up to the periphery of the substrate (Fig. 1 (a)), and as the semiconductor device goes through the manufacturing process (mainly heat treatment), it becomes monocrystal silicon as shown in Fig. 1 (b). Slip 2 enters from the periphery. this is,
This is because strain such as mechanical damage in the peripheral portion of the substrate is caused by thermal stress and, in an attempt to alleviate this strain, does not remain in the peripheral portion but enters the central portion of the single crystal silicon substrate as slip. Therefore, if a semiconductor element is provided on the slip line, it becomes a cause of leakage current, which causes deterioration of the characteristics of the semiconductor device, which in turn becomes a cause of a decrease in yield.

The present invention eliminates the above-mentioned drawbacks, and in particular, by making the periphery of a single crystal semiconductor substrate a polycrystalline semiconductor, the strain at the periphery of the substrate is alleviated, slippage is less likely to occur, and the single crystal semiconductor substrate is It is possible to prevent deterioration of the characteristics of the semiconductor device provided in the semiconductor device and improve the yield.

In the present invention, %Ia means that the peripheral portion of the single crystal semiconductor substrate is made of polycrystalline semiconductor.

Hereinafter, the present invention will be explained in detail based on Example VC.

FIG. 2 shows the present invention applied to a single crystal silicon substrate.

A plan view (Fig. 2 (a)) and a cross-sectional view (Fig. 2 (a))
Figure (b)). That is, the peripheral portion of the single crystal silicon substrate 3 is a silicon substrate made of polycrystalline silicon 4. With the substrate of the present invention, the distortion at the cylindrical side of the substrate is alleviated compared to that of polycrystalline silicon 4Vc, and the slippage of the monocrystalline silicon substrate 3
It doesn't fit in. Therefore, the characteristics of the semiconductor device provided on the single-crystal silicon substrate 3 are not deteriorated and the yield is improved.

Note that the thickness of the polycrystalline silicon at the periphery of the single-crystal silicon substrate may be any desired thickness, but it is preferable that the thickness be approximately the same as the thickness of the substrate. Such a semiconductor substrate may be produced by, for example, growing a single crystal semiconductor, forming a polycrystalline semiconductor on the surface of the single crystal semiconductor by a known method such as CVD, and then cutting out the substrate.

As described above in detail, the semiconductor substrate of the present invention is less prone to slippage from the periphery of the substrate, improves the electrical characteristics of the semiconductor device, and contributes to improved yield.

[Brief explanation of the drawing]

Fig. 1 (aJ is a plan view showing a conventional single crystal silicon substrate, Fig. 1 (b) is a plan view of a single crystal silicon substrate that has undergone a semiconductor device manufacturing process, Fig. 2 (a) and Fig. 2 (b)
) are a plan view and a cutaway view of an embodiment in which the present invention is applied to a silicon substrate. In addition, 2 in the figure shows 1.3...single crystal silicon substrate, 2...
- Slip, 4... River - Polycrystalline silicon.荊1Question C112) 9Fl [Reno] tde 2 times tlln Fig. 2 (Me)

Claims (1)

[Claims] A semiconductor substrate characterized in that the peripheral portion of a single crystal semiconductor substrate is made of a polycrystalline semiconductor.